For many years harvesters, such as agricultural balers, have been used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. Usually, a mower-conditioner cuts and conditions the crop material for windrow drying in the sun. When the cut crop material is properly dried, a harvester, such as a round baler, the most frequently used in the industry, travels along the windrows to pick up the crop material and form it into cylindrically-shaped round bales.
Typically, the forming of a bale is terminated according to a diameter criterion. Depending on the crop and its moisture level, the weight of bales and the dry matter content can vary widely, even within the same field. It would be advantageous to sense and adjust multiple criterion, including bale moisture, to provide a more uniform bales during the baling process.
A variety of sensors are incorporated into a large, cylindrical bale baler in U.S. Pat. No. 5,622,104. In particular, the use of a bale size sensor is disclosed. Additional sensors are suggested for bale RPM, crop moisture, horsepower demands, belt tension, and bale weight. Wild et al. reported a hay yield monitoring system for round balers with strain gages on the tongue and axle of the vehicles, which provided a measure of the weight of the baler and the bale. They also added accelerometers to measure vertical accelerations during operation and determined stationary loads within 2% of actual weight.
A cylindrical bale baler system was disclosed in U.S. Pat. No. 6,378,276. The system comprises an electronic evaluation unit for processing signals from displacement sensors and a pendulum, transmitting the bale weight to an output unit with which the data are displayed or stored, such as on a yield card. Additionally, a control device may control various baler functions. Further, a moisture sensor for crop material may be connected with the evaluation unit for an automatic conversion to weight of the dry mass of the big round bale.
In U.S. Application No. 2013/0160661 A1, a system is described that incorporates various sensors, including ones for diameter, weight, and moisture, an electronic control unit, and a density adjustment system. The system collects historical data regarding bale weights, and adjusts the amount of belt tension applied to future bales to achieve both a target bale weight and bale size. One disadvantage of this system is that the adjustment of the belt tension takes place in between baling cycles and is based purely on previously baled crop. Such a system cannot adjust for crop variations, for example a sudden increase in crop moisture level, until additional historical data is collected.
There is, therefore, a need for a baling system that can measure the diameter, weight, and moisture content of a bale while the bale is being formed, and make real-time adjustments to the density pressure placed upon the bale to correct for any encountered variations in crop conditions. Such a system would provide a more consistent bale weight and size from bale to bale, even when encountering high variations of crop moisture or crop weight.